Steam-boiler.



STEAM BOILER. -APPLIOA'IIDN FILED APS.. 19, 1907.

THE #onlus rl'rsns Co.. wnimlwroli D JOHN A. DOARNBERGER, OF ROANOKE,VIRGINIA.

STEAM-BOILER.

- Specification of Letters Patent.

Patented Apri1'21, 1908.

Application :filed Apri119, 1907. Serial N o. 369,125.

To all whom it may concern:

Be it -known that I, JOHN A. DOARN- BERGER, a citizen of the UnitedStates, residing at Roanoke, in the county of Roanoke and State ofVirginia, have inventedcertain new and useful Improvements in Steam-Boilers; and I do hereby'declare the following to be a full, clear, andexact descriptionof the invention, such as will enable others skilled inthe art to which it appertains to make and use the same.

My invention relates to certain new and useful inprovements in steamboilers and more especially such as are now almost'universally used uponlocomotive engines.

It is well understood by those familiar with the construction and usesof locomotive boilers that the repairs due to leaky joints between thetubes and the flue sheets con,- stitute much the largest per cent. ofthe cost of maintaining locomotives in condition for efhcient work. Suchleaky joints have been principally due to three prominent causes, viz:the variation in expansion and contraction, the vibration of the tubesand the effect of the direct attack of the heat in the fire box upon theends of the tubes in the flue sheets.

Many efforts have been made in the direction of improving the characterof joints between the flues and fiue sheets to render them tight and toavoid as much as possible the destruction of the ends of the tubes inthe back fiue sheet, and success to a certain extenthas attended theseeHorts, but it is a recognized fact the heat from the fire box vwill ofnecessity and in time of greater or less duration, attack the ends ofthe tubes to such an extent as to render it necessary to remove suchtubes and repair the same by cutting off the affected portion andwelding a section of new tubing to the remaining portion then restoringthem to their position. In making such repairs it becomes necessary toremove the front of the engine, the exhaust pipes, netting, sparkarrester &c. before the defective tubes can be removed and in order thatwhen repaired they may again be properly secured in lacefin the fluesheets. The time, labor an expense involved in such Work, especially inlocomo tives of modern construction in which the tubes are of twenty ormore feet in length is 'ing the features o well understood by thosefamiliar with the subject.

My invention has for its object to lessen the time and amount of labornecessary in making such rep airs, and to render absolutely unnecessarythe uniform practice of weldin new sections to the tubes after theremova of t e defective parts or ends, and my invention is renderedpracticable and successful by taking advantage of features ofconstruction involved i-n Letters l Patent No. 823,399, granted to me onJune 12, 1906, and to which special reference is made. In theconstruction covered by said Letters Patent, the joint between the endsof the tubes and the flue sheet is protected from the effects of unduevibration of the tubes through the medium of a reinforcing, auxiliaryflue sheet tied and stayed to the main sheet by suitable bolts.

According to my present invention advantage is taken of the presence ofthis reinforcing and auxiliary flue sheet, and its presence constitutesone of the essential ele ments of my present invention,- which consistsin primarily forming the tubes in two sections a'nd securing one endofeach section in one of the main flue sheets, and the opposite end inthe reinforcing auxiliary flue Sheet, as .will be hereinafter more fullyset forth.

My invention further consists in the special manner hereinafterdescribed of secur` ing the adjacent ends of the tube sections in` thereinforcing, auxiliary flue sheet.

In order that those skilled in the art to which my invention appertainsmay fully appreciate the advantages of the same I will proceed todescribe the construction of my improved boiler referring by numerals tothe accompanying drawing'which represents a vertical section of a art ofa boiler embodymy invention and in which 1, is the front fiue sheet; 2,the back flue sheet, and 3, the reinforcing auxiliary flue sheet shownand described in the Letters Patent hereinbefore referred to, and whichis tied and stayed to the main flue sheet 2, byl boltsl 4, as thereinshown, or by threadin the bolts in the main, and reinforcing, auxi iarysheets as herein shown, or in any other suitable manner.

5 6, is one of my two-part tubes located within the iiue sheets and inposition to be permanently secured therein, and 6-7, represents such atwo-part tube after it has been rolled in the reinforcing, auxiliarytube sheet and also in the back sheet.

7, represents the ordinary copper ferrules employed in making the usualjoints between the tubes 'and the front and back sheets.

While I do not wish to be confined to any exact dimensions, I have foundit desirable to make the reinforcing, auxiliary sheet 3, of one inchgage, or about double the gage of the front and back sheets. Thereinforcing, auxiliary sheet is bored for the reception of the adjacentends of the two parts of the tube, and an annular groove or recess 8,preferably rectangular in cross section, is formed and within which theextreme end of the long part of the tube extending from the front sheetis rolled as clearly shown. An annular shoulder 9, is also preferablyformed to constitute an abutment for the adjacent ends of the twosections of the two part tube, but if deemed desirable this shoulder 9,may be omitted and the front end of the rear or short section of thetube may abut the rear end of the long section. When the opposite endsof the front or long section of the tube is rolled in the front sheet inany well known manner, and in the reinforcing, auxiliary sheet as shown,such section is obviously secured against independent longitudinalmovement, and when the opposite ends of the short rear sections of thetube are rolled in the back, and reinforcing auxiliary sheets which areheld in fixed relation with one another by the tie or stay bolts 4,x thetwo parts of the tubes constitute practically one continuousunobstructed tube. As set forth and illustrated in the Letters Patenthereinbefore referred to the reinforcing, auxiliary sheet 3, may be tiedto either or both the back and front sheets.

From the construction shown and described it will be seen that when therear ends of the short sections of the two-part tubes become damagedthey may in the usual manner be released from the back sheet andwithdrawn from the reinforcing auxiliary sheet and new short sectionssubstituted and secured in position without in any manner affecting thecondition of the front or long sections of the tubes, and renderingtheir removal or handling in any manner or for any purpose unnecessary.

In locomotive boilers of modern construction and in which the tubes aretwenty or more feet in length, when the rear ends of such tubes becomedamaged it becomes necessary as heretofore stated to remove the entiretube, then cut off the damaged portion and restore the tube to normalcondition by welding to it a section of new tubing, testing the weldedjoint, removing the scale and rolling the two ends of the tube in thefront and back sheets, while according to my invention and with mytwo-part tube, additional short sections may be kept in stock andexpeditiously substituted for similar damaged sections.

I do not wish to be confined. to any particular location of thereinforcing, auxiliary sheet and consequent lengths of the two scc tionsof my two-part tube, but it is of course desirable that the reinforcing,auxiliary sheet be located as near as practical to the back sheet inorder that the rear sections of l the tubes may be comparatively short.

I have found from the )ractice of my invention as covered in tie LettersPatent referred to, and in boilers of modern construction with tubestwenty feet in length it is desirable and practicable to locate thereinforcing auxiliary sheet about eight inches from the back sheet, thusrendering it necessary to use correspondingly short rear sections of thetwopart tube. As indicated however herein, I do not wish to be confinedin any manner to any exact dimensions of parts, or to any )articularmanner of securing the two ends of the twopart tubes in the main andreinforcing, auxiliary sheets, as the broad and generic feature of myinvention resides in the employment of tubes made in two parts, inconnection with a reinforcing auxiliary sheet located intermediate thefront and back main sheets and preferably tied or bolted in fixedrelation with one or both of said sheets.

Having described the construction and. advantages of my improved boilerwhat I claim as new and desire to secure by Letters Patent isl. In asteam boiler provided with a reinforcing auxiliary flue sheet locatedin.- termediate the front and back main sheets and secured in fixedrelation therewith; two part tubes each having one end Alixcd in a mainflue sheet and the opposite ends fixed in the reinforcing auxiliarysheet, substantially as hereinbefore set forth.

2. In a steam boiler having` a reinforcing auxiliary flue sheetintermediate the front and back main sheets and secured in fixedrelation to the back main liuc sheet; tubes formed of two sectionssecured at their outer ends within the main front and back sheetsrespectively, and their opposite adjacent ends secured within thereinforcing auxiliary sheet formed with an annular recess, and anadjacent annular shoulder constituting an intermediate abutment for theadjacent ends of the tube sections, substanti ally as hereinbefore setforth.

3. In a steam boiler provided with a rcinforcing, auxiliary fine sheetintern'lediatc the lilront and hack main flue sheets; tWoname to this'specification in the presence oi part tubes each having one end securedin a two subscribing Witnesses. main ue sheet and its o posite endsecured in the reinforcing auxilitry flue sheet and JOHN A' DOARNBERGER5 constituting a continuous flue, substantially Witnesses:

as hereinbefore set forth. W. H. LEWIS,

In testimony whereof, I have signed my JOHN A. PILCHER.

